The present invention relates to wide mouth blow molded plastic containers, and more particularly to such containers having opposed chordal vacuum flex panels which are particularly suited for hot-filling and/or retorting viscous products.
A number of hot-fillable blow molded containers are disclosed having panels that flex due to the hot-filling process. For example, U.S. Patents to: Brown 5,141,120; Brown 5,141,121; Krishnakumar 5,472,105; Prevot 5,392,937; and Prevot D344,457 disclose hot-fillable bottles having panels providing the dual function of affording grippability and vacuum-accommodating flexure. U.S. Pat. No. 5,887,739, issued to Graham Packaging Company, L. P., and owned in common with the present application, discloses a blow-molded wide-mouth container having a plurality of vacuum-flex panels spaced apart about its periphery. U.S. Pat. No. D420,593, also owned by Graham, discloses a pinch-grip wide mouth container. While the patented Graham wide mouth containers afford the advantage of ready scoopability of contents, the flex panels and dome structural intrusions into the container may impede thorough scoopability for certain types of viscous food products. Unlike containers having conventional peripheral flex panels that afford wrap-around labeling, flex panel grip containers of the type disclosed in the above patents have limited labelable areas due to the presence of the unlabelable grip areas between the front and rear label panels.
In retort processing of containers filled with viscous products, such as sauces, the container is subjected to greater internal pressures and volumetric changes than occurs with hot-fill processing. This is due to the higher processing temperatures, and, therefore, the greater expansion of the contained products and associated vapor. In an attempt to provide a satisfactory retortable blow-molded plastic container, U.S. Pat. No. 4,642,968 discloses a cylindrical wide-mouth container having a bottom structure which bulges outwardly to accommodate internal forces developed during retorting. See also U.S. Pat. Nos. 5,217,737 and 5,234,126. U.S. Pat. No. 5,908,128 discloses a narrow-neck bottle having a plurality of peripheral flex panels that accommodate internal forces due to pasteurization. The ""128 patent does not provide ready contents scoopability because it has a narrow neck and is encumbered with a plurality of internal flex panel structural elements that interfere with contents scooping.
There is, therefore, a need for a wide mouth container having a simple flex panel that presents a minimum of structure that can interfere with scooping of contents yet which is effective in absorbing vacuum without undesirable structural problems. There is also a need for such a container that provides a maximum amount of surface area for labeling. Furthermore, there is a need for a retortable wide mouth container that can be produced by economical extrusion blow-molding technology.
With the forgoing in mind, an object of the present invention is to provide novel hot fillable plastic containers which have vacuum absorption panels that flex during hot-filling, capping and cooling; which are resistant to unwanted distortion; and which have a minimum of internal structure that could impede thorough contents scooping.
Another object of the present invention is to provide wide-mouth, blow-molded jars having flat flex panels that present minimal interference with out-scooping of contents by a consumer and that maximize labelable areas.
A further object of the invention is to provide a wide-mouth, blow-molded jar structure that can be used in either hot-fill processing or in retort processing.
Yet another object of the invention is to provide a wide-mouth, blow-molded retortable jar that can be produced by conventional extrusion blow-molding technology.